1. Field of the Invention
The invention is concerned with a novel group of compositions. It more particularly relates to a grease composition comprising oil, hydroxy-containing soap thickener and borated long chain alcohols, optionally containing phosphorus and sulfur moities.
2. Discussion of the Prior Art
With respect to the novel compositions of this invention, no prior art is known that teaches or suggests them. However, alcohols and mixtures of alcohols have been used as intermediates in the manufacture of a variety of lubricant additives, although the use of alcohols themselves has not been widespread lube oil additives because of potential oxidative and thermal instability and volatility difficulties. It has been found that the borated alcohols in combination with the particular grease thickener and the phosphorus and sulfur moieties provide dropping point characteristics in greases that the non-borated compositions do not provide. The grease compositions disclosed herein are, to the best of applicants' knowledge, novel, although some borated alcohols have been used in the past in commercial lubricant formulations to provide improvement in lubricity properties and have also, on occasion, been used in brake fluid formulations.
For example, U.S. Pat. No. 2,160,917 discloses lubricants containing low molecular weight borate esters, e.g., borate esters containing from 4 to 12 carbon atoms. The disclosed borates include the tributyl and trilauryl borates. Other patents include U.S. Pat. No. 3,014,870 (to mixtures of amine and certain boronic mono- or diesters); U.S. Pat. No. 3,108,966 (aryl boronic esters and thio acid ester lubricants); U.S. Pat. No. 3,133,951 (fuels containing dialkyl boron esters); U.S. Pat. No. 3,347,793 (tertiaryalkyl boron esters) and U.S. Pat. No. 3,509,054 (esters or boron acids with 2,6-dialkyl-phenols).